A liquid-level gauge, also referred to as a liquid-level meter, is an instrument for measuring the level of a liquid, so as to indicate any change in the level of the liquid and accordingly the currently available liquid quantity.
The liquid-level gauge is usually used to measure the level of a liquid stored in a container. The liquid can be any kind of critical liquids, including but not limited to fuel oil, industrial raw material, drinking water, and fire-extinguishing agent. In many important infrastructures, the management of critical liquid storage is of highly important. For example, to avoid undesirable operation interruption, hospitals and nuclear power plants must always have back-up fuel generators to provide emergency power supply in the case of a power failure. Therefore, it is very important to use a liquid-level gauge that is able to provide accurately measured value of fuel storage.
There are various types of liquid-level gauges designed according to different operating principles. These liquid-level gauges are quite different in terms of their reliability and sensitivity. Liquid-level gauges having similar designing principle but supplied by different manufacturers are not necessarily equal in the reliability thereof. Therefore, it is desirable to work out a way for effectively and efficiently testing and comparing different liquid-level gauges to ensure their reliability and sensitivity.
In a conventional way of testing a liquid-level gauge, a liquid container having a draining device is prepared. Water or other liquid is filled in the liquid container. The liquid-level gauge to be tested is disposed in the liquid container to obtain a measured value. Then, the draining device is turned open to drain off a predetermined quantity of water or liquid before being closed again. Thereafter, use the liquid-level gauge to measure the water or liquid remained in the liquid container to obtain another measured value. The quantity of the drained water or liquid is also measured and converted according to a bottom surface area of the liquid container into a level change value, i.e. a reference value. Compare the reference value with the value measured by the liquid-level gauge (i.e. the measured value) to determine the reliability and sensitivity of the tested liquid-level gauge.
The above-described conventional liquid-level gauge testing method has some disadvantages, such as requiring a lot of time to conduct the testing procedures, and requiring additional numerical conversion before the procedure of comparing with the measured value of the liquid-level gauge. Further, it is uneasy to control the draining device and the volume of drained water or liquid varies each time. There is also the problem of remained water or liquid in the draining device. Therefore, the conventional liquid-level gauge testing method is subject to uncertainty as a result of the above problems.
It is therefore tried by the inventor to develop an improved liquid-level gauge testing device and method to enable increased liquid-level gauge testing accuracy with simplified testing procedures and reduced testing time.